In the past there have been a number of attempts to make removable cartridge or media disc drives with varying degrees of success due to the difficulty in designing a compact, efficient, highly accurate and repeatedly operable disc drive arrangement at a reasonable price and within strict form factor constraints. Prior removable cartridge disc drives have form factors which include trays which must be selectively extended from the drive for receiving a cartridge and/or in addition buttons and levers which extend from the drive in order to facilitate the operation of the disc drive. Such designs are not satisfactory as they can tend to block the operations of a computer or other computer peripherals which are positioned adjacent to the disc drive. In addition when buttons and levers extend from a drive there is always the possibility that these members can be accidently touched or repositioned causing data to be lost.
Another consideration in the development of removable cartridge disc drives is that of accurately receiving and seating a cartridge in the drive and accurately and efficiently loading the disc drive heads onto the media in the cartridge. It is important that the cartridge be locked into position and that the heads not be damaged during the cartridge loading or cartridge unloading processes. Further it is desirable that should there be power failure, that there is a convenient and efficient manner of removing the cartridge without damage to the memory media or the heads. This is especially important when there is proprietary information on the cartridge which needs to be placed in a secure location when not being used. With many prior art drives it is very difficult to remove a cartridge without power to the drive and even if the cartridge can be removed there is the possibility that there would be damage to the recording media or to the drive heads.
With any prior art drives there is a need for the development and use of an appropriate actuation mechanism for efficiently and accurately positioning the head relative to the recording media. In the past both stepper motors and linear voice coil motors have been used. In the case of stepper motors, the discreet position of the stepper motor limit the track density of the media. In the case of the linear voice coil motors, while the heads are infinitely positionable, such motors have not been found to be cost effective a radial voice coils.